Surfing the wave of coverage of this morning’s report by the Intergovernmental Panel on Climate Change? This Q & A piece in the Guardian UK is short, sharp, and to the point—a great starting place for neophytes (and big-picture types).

The heart of the matter:

What does [the IPCC report] say?

Emissions of greenhouse gases are expected to further change the climate over the next 100 years, it says. As a result, sea levels will rise over the century by around half a metre, snow will disappear from all but the highest mountains, deserts will spread, oceans will become acidic, leading to the destruction of coral reefs, and deadly heatwaves will become more prevalent.

While it predicts severe melting of Arctic ice this century, and of the Greenland ice sheet over the next few hundred years, it suggests the much colder Antarctic ice sheet will grow with increased snowfall, offsetting about 0.1 metres of sea-level rise by 2100.

A big rise in sea levels would be catastrophic, with millions of people forced to leave their homes, particularly those living in tropical, low-lying areas. This will create waves of immigrants into countries that may struggle to cope with the influx.

Crucially, the report points out that a lag in the global climate system means average temperatures will continue to rise by 0.1C a decade even if all sources of emissions were frozen today. And it says forests, oceans and soil will become less able to absorb carbon dioxide, which could contribute another 1.2C of warming by the end of the century.

In total, world temperatures are likely to rise by 3C by 2100, but they could increase by as much as 5.8C.

For me, the first question that this raises is: given that, because of human actions already taken, global temperatures might continue to rise for generations, how can we understand the role of climate-change activism now?

The Guardian piece credits the IPCC report with saying that “even if we change our behaviour today, the planet will become a more dangerous place.”

How, then, do we think and feel about changing our behavior “today”? Is reducing carbon emissions a duty that we must carry out on behalf of humans living two or three hundred years in the future? Is it a moral imperative we must observe, even understanding that it won’t make a difference to ourselves and our children? Can we still convince ourselves of its relevance, and if so—how?